The present invention relates to a supercalender apparatus for smoothing the surface of a web by passing it through the nip between a metal roll and an elastic roll. More particularly, the invention relates to an improved supercalender apparatus in which the elastic roll does not develop cracks due to shrinkage after shaping and in which the elastic roll has an improved resistance to heat and pressure in service.
As shown in Japanese Published Patent Application No. 36704/79, a highly heat-resistant and pressure-resistant elastic roll for use in a supercalender apparatus is conventionally manufactured by winding a fibrous material about a metal roll (core) and impregnating the fibrous material with a polyamide resin. A elastic roll has also been proposed that uses a core metal roll wherein the fibrous material is not wound about the core metal roll but instead a polyamide, polyurethane or epoxy reson blended with a filler such as quartz powder or carbon black is fixed to the surface of the core roll. However, as the outside diamter of the elastic roll is made larger, more cracks tend to develop due to shrinkage after shaping of the roll. Furthermore, an especially significant problem with the elastic roll having a polyamide resing coating has not been solved completely, that is, it becomes more difficult to maintain a desired surface temperature for the elastic roll as the operating temperature is increased so that the roll can easily be deformed.